Kingdom Hearts: Remnants
by Hydriatus
Summary: All travel to save their worlds. Even if their worlds do not deserve to be saved.
1. Chapter 1

**Chapter One**

_"There is a natural order to things...Light and darkness existed in the worlds long before those of us with thought. So who defended the worlds back in that time? There were no keyblades, for there were no masters to wield them. I have pondered this and come to one conclusion: the worlds fashioned weapons for themselves to hold back the darkness..."_  
><em>-Unknown Report 8 (A)<em>

Ropes creaked with strain, swaying gently as a strong wind howled around the cliffs. Holding onto the rope tied to the metal rungs of the platform, Leon merely narrowed his eyes and turned his head away. The wind blew against him, not strong enough to push him from the crates that were being hoisted up, but with enough force for him to tighten his grip on the rope. Yuffie would undoubtedly be berating him if she were present. Something about choosing to take the lift rather than the stairs as being theatrical, which was nonsense of course. It was the fastest and most direct way to reach the castle.

The young man peered down, still able to make out Cid arguing with a worker over something or other next to a large pile of stones. Piles of building materials were scattered all over the chasm floor, harvested from the rocky faces of the canyons running throughout this part of the world, as well as the few forests they could find nearby which hadn't been destroyed during the Heartless occupation. The latest delivery of materials was even now making it's way towards the castle. Leon couldn't help but smile slightly as he caught sight of Cid's airship, the Shera. The young man couldn't quite understand why, but seeing airships had always filled him with a feeling of...nostalgia? That was probably the best word for it. As if he had a pleasant memory attached to one, a memory he could never quite grasp.

Leon looked away from the incoming airship, looking up as the platform finally reached the lip of the cliff on which the castle, the symbol of their home, rested. Hollow Bastion was an imposing sight, even in it's current state of disrepair. The Heartless attack had caused a large amount of damage. Of course, the town had been almost entirely annihilated, but there were precious few injured – the defense mechanisms built into the settles areas had managed to keep the monsters at bay long enough to evacuate everyone to the fortress. There the militia had managed to deal with the few Heartless that made it past the perimeter the Hollow Bastion Restoration Committee had managed to set up beyond the walls of the town.

There was a clunk as the crates were swung sharply around to hang next to the sheer wall of the castle, before being lowered gently to it's base. Leon let go of the rope and hopped down to the ground. He landed roughly, dropping to a crouch to avoid losing his balance and landing face down in the dirt. To any onlookers, it merely appeared as if he had dropped into a combat stance, more out of habit than the possibility of any attack. The young man stood up and dusted his trousers off, before heading off to one of the many entrances to the inner castle littering the exterior walls.

He was not looking forward to the task ahead, one the Restoration Committee members took turns to perform. Not that it was difficult or dangerous, but because it involved knowledge beyond his understanding. Cid was much better at dealing with machines, but currently he was busy aiding rebuilding efforts. So it fell to Leon to work on Ansem's computer terminal. Hopefully that Tron program would be around to make things easier. Leon was no computer expert – the most he ever did with one was check the schedules for his classes back when he was still being schooled. He had always preferred being in the training center, battling the resident beasts.

A sigh was the only sign of his feelings on the matter as he continued walking into the darkness of the castle. He briefly wondered how the others were doing as he took a moment to orient himself in the corridor before heading for the chamber with the computer.

* * *

><p>The tower was silent. It had been abandoned a long time ago by that witch everyone seemed so afraid of. However, there were still many Heartless prowling about. Nothing she couldn't handle! Another of the small black critters exploded into motes of light, a heart barely visible before fading away along with the remains of the creature. Another monster, human yet not, launched itself at her. It reached out with it's claws, ready to tear into her body, only for a boot to smash against it's face, sending it flying back the way it came.<p>

Tifa's clothing spun around her as she completed her spin, bracing herself in place as she unleashed a flurry of punches at yet another neoshadow. The creature seemed to look almost sad as she crushed it beneath her blows, it's body also falling apart into light. She felt nothing but elation at another victory. The feeling kept her alert, kept her eager for combat, made sure she did not fall into a pattern or lose her focus. Her head swiveled in nearly all directions as she scanned the corridor for anymore enemies. But nope, there were no more. That was surprising. This place had been that witch's stronghold for a fair number of years – it practically reeked of darkness. Yet there were half the Heartless she had expected. And the numbers she had to face steadily decreased the higher she climbed the tower. It was almost as if she was chasing someone up to the top, only having to fight the Heartless that had managed to spawn in the wake of the other intruder, rather than the horde that was undoubtedly still here after the battle.

So someone else was in this tower. The key question, was who? Nothing that could have aided her in identifying the person who had traveled this way before her presented itself. A part of her hoped it was _him_, but that would have been too ideal. No, more likely it was another spiky-haired member of the Hollow Bastion Restoration Committee. But then again...she was over-thinking things. She'd find out once she caught up!

Which would be pretty much about now. She had finally reached the top of the tower, and she was pretty sure that the large, double-doors at the end of this corridor led to some inner sanctum or sorts.

Tifa approached them and reached out, gently pushing one of the doors. It refused to move. She frowned slightly. Had her quarry (as that was the label she had applied to whoever was moving through the tower before her) sealed it behind themselves? Or had they merely not made it this far? Or maybe she should pull the door instead of pushing it?

Her last guess was the correct one of course, and the trained fighter easily hauled the heavy wooden door open, peering cautiously into the darkness beyond. She could make out a window far ahead of her, but it was covered by a heavy and dusty curtain, the light weakly shining through it in small patches, pooling on the stone floor of the chamber. Tifa blinked several times and waited for her eyes to adjust. Then a frown marred her features as she saw what was inside.

Nothing, and no one.

Oh sure there were shelves and bookcases, but they were all empty. The chair and table were knocked over, and the doors of a cabinet were hanging open, the interior just as bare as the room. Nothing here at all. She sighed as she entered the room properly to look around. She could still report this to the Restoration committee, though she didn't know if this, an empty room, was really worth reporting. The decline in Heartless certainly was though. That kinda made this whole trip worth it, even if she couldn't find him!

Shaking her head as she considered where to search next, Tifa left.

* * *

><p>Cid sighed as he leaned back in his chair, gazing at the ceiling. He had managed to make it back to Merlin's house, and had been looking over Radiant Garden's new defenses. The claymore system had overloaded at the height of the battle, and now he spent every free moment he could get trying to design a replacement. Without it, Heartless would be able to prowl the streets, attacking whoever they came across. It would be like Traverse Town all over again, with people living in fear.<p>

Luckily, the minions of darkness seemed content to mill about beyond the broken walls of the town, the odd invader here and there swiftly eliminated by either Cloud, Squall, or Yuffie. None of the Heartless had managed to make it into the town, but no one was taking any chances. The entire population was still being accommodated in Hollow Bastion itself, until the walls of Radiant Garden could be repaired and a new claymore system installed. Both of which were his responsibilities.

Cid sighed again. It was going to be a really long week. Thankfully he had managed to find the Shera again, and that was making the repair work proceed much faster than he could have hoped for. A smile came to the pilot's face as he remembered the day the Committee had discovered the chamber where he had hidden his precious airship before they had been forced to evacuate the world. They had taken the Highwind in that occasion of course – a tried and tested airship was much easier to pilot in stressful situations that an untested prototype. It's loss still stung at Cid's heart.

Still, as soon as Radiant Garden was rebuilt, he was going to have the engineers work on a new ship, one to protect their world like never before. The blond man nodded to himself as he sat back up and resumed his work. Oh yes, it would unleash their judgment upon the Heartless and their ilk. Should the Darkness ever make it's way back to their world, it would no longer find it as helpless as it had been before.

* * *

><p>Leon groaned as he rested his head on his hands. This computer work was boring in the extreme. Tron was busy with something or other, so he was left on his own to trawl through all the figures and symbols, trying to decipher them into useful information. Most of it seemed to be mathematical formulas, or written with terminology that made no sense to him. He wished he could do something else, but he had already trawled through the accessible text documents and images. Some of them were quite...disturbing. The research Ansem's apprentices had undertaken regarding the power of hearts was...scary in its clinical detachment.<p>

He suppressed a shudder. Though he was a soldier, a fighter, and had seen his fair share of carnage, there was something innately wrong about seeing something like what the apprentices had done. The strange letters, numbers and symbols continued to scroll over the screen in front of him. Leon looked over the computer, to the giant hall stretching out before him. The Committee had never managed to puzzle out exactly what the place was for. Merlin had suggested it was some sort of place to run tests, possibly on the Darksides. Cid argued it was for the assembly of artificial Heartless of some size, such as the Guard Armor Sora had destroyed in Traverse Town.

Of course, there was a chance that both possibilities were true. Leon had heard of giant Heartless terrorizing many worlds, all bearing the emblem that marked them as artificially created. But if that was true, then where was all the machinery that would have been required to fashion them? Or to study any Darkside? The possibility that it had been moved before they had managed to retake Radiant Garden was an unpleasant one, but also the most likely. Though there was a possibility that this hall had been used for something else entirely, it was safer to assume the worst and be pleasantly surprised than the other way around.

Then again, if any heavy machinery had been moved, then it was bound to leave a trace, a trail to follow to wherever the artificial Heartless spawned. He would have to talk to Yuffie about the idea of following whatever had been removed from the Bastion, if indeed there had been anything originally to remove.

* * *

><p>Five figures walked along the ancient path that pilgrims trod aeons before. Their footfalls were heavy, and echoed off the chasm's walls. The clink of metal on metal, and the occasional swish of clothing were the only other sounds. Not one of the figures spoke. One marched with it's head hung low, staring at the ground as if in a trance. Another was merely bored, it's eyes glazed over as it retreated into the entertainment that were it's memories. The third conveyed no emotion as it marched forward, inexorable in its movements. The fourth was idly noting down some thoughts in a journal it carried. The leader of this little band was at the forefront, leading the way with a staff, it's eyes fixated on some point in the distance, beyond the walls of the chasm they were in.<p>

They had been walking like this, over and slowly into, the surface of the world for a long time now. Not one of them had spoken the entire journey, each of them content with the silence of the others. Only the leader of this little expedition knew why they were out here, but none of the others cared. This was just another journey for them, another boring and silent journey. The fourth idly snapped it's journal shut and stowed it away in it's coat, as the leader turned it's head and altered it's course, heading for a large crack in the chasm wall.

The group followed it as they entered a tunnel filled only with darkness. None of them shirked away, and they strode in unopposed. They did not need light to see in any case. The tunnel itself ran for about three hundred feet, leading steadily downwards, before giving way to a colossal chamber, deep beneath the surface of Radiant Garden, illuminated by the pale crystals sprouting from the walls. The lead figure raised a fist and the group stopped, allowing their current leader to step into the chamber alone. It's head moved slowly from left to right as it surveyed the surroundings. The cavern was huge, but covered in oddly shaped growths of crystal, blossoming from everywhere like explosions.

It walked up to one of the blossoms, one that sprang from the cavern wall. Reaching out, the figure placed a hand on the clouded crystal, wiping away the moisture to reveal the clear surface beneath. And the dull, creamy white of what was inside. The figure smiled as its eyes traced the hazy white shape upwards, into the core of the crystal. A link to the heart of the world. One of it's fabled WEAPONs.

* * *

><p><em>AN: Oh yeah. I'm back! Been a long time since I was here, so let's see if I still got the touch, eh? _

_Yes, my other work will be getting updates as well. OTT and IS:LT. _

_As for this...well, let's face it - we all want to do at least one massive multiplayer crossover right?_


	2. Chapter 2

**Chapter Two**

_"The Door to Light. What is it? Why does it exist? Questions, questions...the more I learn, the less I know. Yet I know that this is the key. The knowledge of the Door and what lies beyond...that is what will end my journey. I am sure. Now I must merely find it. The Eye may try to hid it from me, but somewhere in it's depths I will find the Door. And when I open it, I will know power."_

_-Unknown Report 2 (A)_

Yen Sid Sat in his tower, scowling. He was in his study, sitting at his desk. A crystal ball rested on a small dais before him. The wizened mage had been trying to scry, not a particular person, object nor place, but the future itself. It was more of a habit than any actual desire to see what could occur on his part. Key moments in time were fixed and could be prophesied, but events were so malleable due to free will that most of the time, it was simply impossible to predict them.

At least in literal form. Symbols were easier to see, though their variety of meanings tended to make the future less clear than a simple educated guess based on a firm grasp of action and consequence. Today did not disappoint. The imagery he had seen had been...confusing. But he did not let it worry him. All things became clear in time, and with the Darkness beaten once again by a Keyblade wielder, time was something the worlds had. Yen Sid closed his eyes as he brought up the images he had seen in his mind.

The painting of a ship, and a knocked over ink bottle, spilling it's contents onto the artwork.

An orb, white on top and black beneath. Both halves kept separate by a thin gray band.

A chessboard, on which a knight became a king.

And of course, a shining key, holding back the darkness.

Well that last image was probably the easiest to understand. Sora. The light that had saved so many worlds, that had defeated so many Heartless. The boy was gifted, and had done well despite lacking a teacher. It was a shame none of the old Keyblade Masters could be located. They would have been able to hone Sora's skills further, to make him into a true champion of light. But for now, he was still a boy. One with great skills, but still just a boy. Now the others...those were tricky, even for a mage such as him.

The chessboard for example – it signified conflict, intellect, armies. A black knight becoming a king...well apart from such a thing being impossible in chess, it signified promotion of some kind. Probably amongst those who drew their power from darkness. But that in itself was no need for worry. Concern yes but not worry. Yen Sid had lived for long enough to know that white was not necessarily good, nor black evil. So all he could be certain of from that particular vision was that in a great battle, one between great minds, an underling would rise to power. And not just any underling, but a powerful one.

Now the orb...that one he had no true idea of. Whatever it was, it was split between light and dark. No side had dominance, but that may be more due to the grey band keeping both separate. Hmmm. Grey. A mix of both black and white, of light and darkness. He stroked his beard. That would be a great enigma to puzzle out. Perhaps he should discuss it with Merlin? Though the other mage was often busy aiding in the restoration of Radiant Garden, he did provide Yen Sid with a...different perspective on things from time to time.

As for the ship...that worried him. The easiest conclusion was a vessel, filled with refugees from a world that had fallen to darkness, still being pursued. If that was true, and there was a possibility that it was, then something would have to be done. Luckily, the vague notion of "ship pursued by darkness" was enough information to go on for a scrying attempt. Yen Sid's brows furrowed together as he focused his energies, placing both hands on the crystal ball. Slowly the fog inside began to swirl, a small black dot congealing in the center of the hazy mass. Lazily it began to grow, as if acquiescing to Yen Sid's efforts on it's own terms. But then he could see the ship.

Ships, in fact.

It was an entire fleet. And no two of the craft looked the same. They seemed to be sailing through the void, much like gummi ships, but these were not the vessels of light he was used to. No, the shapes were wrong, too smooth in places. Quite unlike any of the craft he had ever seen travel between worlds. Except perhaps those of the Keyblade Masters, but those were small, large enough to only hold one person. The craft he was seeing...he brought his view closer to one of them. Small twinkling lights adorned it's sides. His sight closed in on one, finding it to be a window. He let out a breath he had been unaware he was holding. The size of the ships was enormous. So many lives, so many hearts. It was as if this fleet was a world itself, constantly being hunted and harassed by the darkness.

The elderly mage blinked and the image was gone, replaced by the fog. He leaned back in his chair, a small bead of sweat running down his temple. Something had to be done. Sora of course would have been the ideal choice, but Yen Sid was loathe to call upon the boy so soon after his victory over the Organization. He had earned his rest, for now. But who else could he send? The warriors of Radiant Garden had their own troubles to deal with, and only a Keyblade Master could cross the void with anything resembling haste. As unfortunate as it was, it would have to be Sora. Now the trick was to find a way to contact the boy...

And then the master wizard smiled. The King. Of course. He was a Keyblade wielder himself. He could locate Sora easily enough. Or his dog, Pluto. Yen Sid had never really questioned how the hound was able to cross the barriers between the worlds so easily, since he suspected the answer would only provide more questions. Of course, he could just ask the King himself to go, but Sora was much more of the type to go off and help people. He did not have royal duties to attend to after all. And his friends were all capable fighters...yes, sending Sora was probably the best chance those people had of survival.

* * *

><p>The people of Radiant Garden slept. They slept in the vast halls and corridors of Hollow Bastion, on makeshift beds and cots. Though unhappy at being kept from their homes despite the absence of a threat, they understood the caution. Until the town's defenses were repaired, they were safest within the walls of the Bastion. Yuffie sat on the roof of one of the towers, wrapped in a cloak to ward off the cold of the air and the shingles she was sitting on.<p>

The night sky was always so serene, much like the landscape. Nothing but endless blue plains, stretching as far as the eye could see. The great gouges crisscrossing her sight were nothing more than scars, a painful reminder of the wounds this world bore. But they were scars that could be borne with pride. Darkness had come and infested this land, and they had managed to drive it back and contain it.

The young ninja stood up, easily maintaining her footing on the slippery shingles. With an effortless bound, she flew from the top of the tower, landing with barely a sound on the roof of another, shorter tower. She barely made a sound. Her skills had come along way since her regular patrols of Traverse Town. There the resident shad often complained about the noise she caused when she ran over their roofs. Of course it was all in good-nature, as they recognized her contribution towards keeping the town safe.

Her eyes narrowed as she scanned the surrounding landscape from her new vantage point. There didn't seem to be anything wrong. But then again, appearances were always deceiving. As if on cue, she heard a low rumbling, almost like thunder. And then came the cracking. Her eyes narrowed as she spotted the source of the noise. A large tear in the ground was forming, marking out a rough circle, about 10 miles north of Hollow Bastion.

And she could only barely make it out thanks to the ground collapsing in on itself in that region. A pit was forming, the tremors suddenly striking Hollow Bastion like a blow. The entire fortress shook, yet Yuffie kept her balance on the slender tower without difficulty. Well that certainly looked like trouble alright. She jumped backwards, off the tower roof, and slid down the surface of it's wall. She couldn't quite keep a smile off her face. They may have to fight soon! What fun!

* * *

><p>The hum of the teleporter died down, letting the giant crystals crash into the metal deck. Some of the servitors shook as the floor beneath them vibrated violently, though Magus Technis had no such issue, his magnets keeping him securely anchored to the floor of the hangar bay – the only place where they had enough room to safely teleport the crystals. The Magus moved over to the nearest crystal, the treads that had replaced his legs whirring slightly as they dragged him over the corroded metal.<p>

The faded red robe he wore shifted slightly to allow the numerous mechanical manipulators hardwired into his body too snake out and reach for the nearest crystal, roughly L-shaped and towering over him. One of his mechandrites reached out and affixed itself to the crystal, inserting a small drill as it extracted a small sample of the substance. Another tentacle-like mechandrite, this one terminating in a small horned skull with glowing eyes, snaked one way and then another, scanning the surface of the object in front of Technis. Carbon in a diamond lattice. In such size...no wonder his drill was having difficulty scratching the surface. They would need something a bit more brutal if they were to obtain any samples.

His mechandrites withdrew, sliding back beneath his robe as he rolled away, half-turning so his compound right eye could focus on the giant black claw descend and take a hold of the furthest crystal, the one with traces of emerald in it's structure. Small groups of tech-magi were scuttling in all directions, trying to be the first to study the strange...things...the Chosen had brought on board. The machinery that could supposedly tear the heart from the body they had brought onto the ship had evoked a similar reaction. But that had been before Technis had the rank of Magus. He had not been permitted anywhere near the strange devices. Now...well not much had changed. The great beings, creatures that were the personification of a world's heart, were encased in enough diamond to make their extraction difficult. At least if the Chosen wished for them to be whole.

Technis did not doubt that a specially tuned melta would be able to produce some results, or maybe even the volcano cannon, but that would have the drawback of leaving their trophies as super-heated puddles on the floor. And the consequences of that...would be unpleasant. Technis cocked his head to one side as his mind ran the calculations. Meltas would be good for burning away the outermost layers of diamond, but the weapons would be irrevocably damaged after a single shot. The power cells would have to be overloaded to the point of explosion, and the resultant energy being projected would melt the gun itself.

Perhaps an Obliterator would be able to do it? Their deamonic flesh gave them far higher tolerances than possibly in the material realm, but since the loss of the warp, all members of that order kept themselves distant from the other factions on the ship. Much like the possessed, they felt the loss of the damned dimension on a much more instinctual level than the rest of the crew. They knew that for now, there was no way to create more of their kind. They were an endangered species.

That thought would have made Technis smile, if he still had lips. Instead, he just giggled to himself in a low pitch whine, muffled by the grille he wore instead of a lower jaw. It would make them more reliant on the Dark Mechanicum than ever before. A nice counterbalance to the possessed the Covens had at their disposal. Technis reversed away from the crystal he had been inspecting as another claw closed around it, lifting it into the air to be transported Chosen-knew-where. His treads squealed slightly in protest as he turned in place before rolling out through the hangar deck towards the lifts that would take him to the corridor that led straight to the engines.

Master Machina would most probably want his report about the latest scheme the Chosen were performing.


End file.
